Apparatus for operating lathes



June 20, 1950 c. A. BICKEL 2,512,008

APPARATUS FOR OPERATING umss Original Filed March 21, 1941 2 2 a 2 l I l I i y cwma: srcto 9 Meamman za'zmzzss" :l

CLI-FCRDABICKEL ATM Patented June 20, 1950 2,512,008 APPARATUS FOR OPERATING TEES Cllil'crd A.

Monarch corporation of Ohio Bloke], Sidney, Machine Tool Ohio,

Designer to The Oo.,

Sidney, Ohio, a

Original application March 21, 1941, Serial No. 384,507, now Patent No. 2,888,757, dated November 27, 1945.

ed an January 22, 1945, Serial No.

11 this application 578.991

8 claims. (CI. 82-!) 1 This invention relates to larly to from the spindle It is an object A further object is to efl'ect the aforementioned control by directly varying the speed of the motor driving the work.

A still further object is to maintain the latter constant.

The single figure of the drawing of my invention shows apparatus which functionally is similar to that of Figure 1 of my parent application,

2 Patent No. 2,889,757, issued Nov. 27, 1945, of which this application is a division.

In my invention a diil'erential is used to compare the speeds of a shaft driven by the lathe motor with another shaft driven proportionately to the instan surface cutting speed of the lathe.

In this arrangement th motor ll provides the power for driving the variable speed transmissicn 81 by means of a motor shaft 38. The output shaft ll of the variable speed transmission has fixed thereto the pulley 40, while the pulley ii is fixed to spindle Belts 2 connect pulleys l0 and H to drive the spindle at a speed determined by the adjustment of variable speed and may be operated either mechanically, hydraulically or electrically. Th tra ded with a control proportional to spindle I. A differential control mechanism indicated generally by numeral ill is associated with disc 49 and a control rod II, the motor 80 and the variable speed drive I! to work being turned;

This control mechanism consists of a rotatable afriction wheel II fixed therea circular rack 8| meshing and driven by a gear II secured to one end of control rod II. The friction disc II is arranged, to be in continuous engagement with the wheel I! and is movable radially thereover for the purpose subsequently to be described.

The cylinder I2 is splined to shaft 88 so as to rotate the shaft while being reciprocable thereupon. The lower end of shaft ll carries a bevel gear 51 forming one side of differential 8i! and which in turn meshes with a pair of planetary bevel gears I and I9. These bevel gears are carried upon shafts 6B and ti which are mounted in a planetary ring gear 82. A bevel gear 83 forming another side of said differential also 'meshes with planetary gears BI and I9. This gear It is carried upon shaft Bl extendina from change speed mechanism 85 and comprises the output shaft of said mechanism, while the input shaft 85 thereof has a bevel gear 88 connected thereto in mesh with a bevel gear 81 fixed to the shaft 38 of motor 80. Change speed mechanism 65 is provided with a control wheel 88 extending therefrom and arranged for manual operation. This change speed mechanism is similar in operation to the variable transmission 22 application, but is since it is not included in the spindle driving mechanism, and therefore, is not required to transmit power between the motor 38 and the spindle l. A lathe carriage 88 carries a conventional cross slide III adapted to be operated by rotation of cross feed screw H driven in a conventional manner by gears 12 and It. A gear 14 is attached to cross feed screw H and drives a chain of gearing It, 18 and 11. Gear 11 has a bevel gear connected therewith which in turn meshes with a bevel gear I8 connected to drive gear 19 integral with a sleeve ll! iournaled on control rod l.

As in the parent case, a sleeve ll having 'a worm wheel I2 fixed thereto is journaled upon control rod 5i and is adapted to be rotated by means of a worm l3 and a handwheel 4 connected thereto. Sleeves no and iii are in spaced relationship along red I and have facing clutch teeth adapted to be selectively engaged by corresponding clutch teeth formed on the end of an intermediate sleeve 85 splined to red 5i and located between sleeves 80 and Bi.

8| s provided on the carriage is connected to axially move sleeve 85 whereby said sleeve may be brought into operative engagement with sleeve when sleeve l! is in engagement with sleeve lll, automatic operation of rod Si is provided whereby sleeve is moved axially to shift disc 53 radially over wheel 40 by and in proportion to the position of cross slide Iii with respect to the axis of spindle i. When sleeve 8! is in engagement with sleeve 8| manual control over the spindle speed is afforded. At this time variations in the speed of spindle I may be affected by the rotation of hand wheel Bl as will be obvious from inspection of the drawing.

It will be understood that motor 38 operates to drive spindle I through variable speed transmission 31. This motor is a constant speed type and, therefore, its shaft will operate to rotate shaft 88* forming an input of change speed mechanism 85 at constant speed. Likewise, for each setting of handwheel 68 of change speed mechanism '5, output shaft 64 and its attached gear I will also operate at constant speed. Since the fri tion disc 53 is rotated by wheel it, the gear 1 will be rotated at a definite speed for each setting of disc 53 radially with respect to wheel IS.

The differential 50, therefore, provides a mechanism whereby ring gear 82 will be rotated whenever there is a difference in the speeds of rotation of shafts 88 and 64 to thereby and eflect the necessary adjustment of control ll of variable speed transmission 81.

Stated in another way, the differential it compares the speeds of shafts 58 and 84. If these speeds are equal and opposite, no rotation of planetary ring gear 62 and no adjustment of control mechanism II are effected. However, for example, as the cross slide Iii moves toward the work axis of rotation so that an increased spindle speed is necessary to maintain constant surface cutting speeds, disc 53 is correspondingly moved radially inwardly over wheel 48 through the drive to control rod I previously described.

This movement results in a reduced rate of rotation for shaft 58 and as the two speeds of shafts 8B and 84 are now unequal a rotation of ring gear 62 results at a rate proportional to the difference in rates of rotation of said shaft. Shaft M is thereby driven to adjust control mech anism 43 to thereby increase the rate of rotation of output shaft I9 relative to the input or constant speed shaft of motor 36. As a result of the increase in speed of shaft 39, spindle l on wheel I! is rotated at a faster rate. This increase in rate continues until shaft 56 is again being driven at the same speed as shaft Bl whereupon rotation of ring gear 62 ceases. It will be understood that the action just described is smooth and continuous as the cutting radius of the tool varies so that the spindle speed is, in the example given, progressively increased in a stepless manner to at all times maintain constant the surface cutting speed.

To obtain constant surface cutting speed with this mechanism the cutting tool carried by the cross slide I0 is positioned adjacent the workpiece at the largest diameter that is to be turned.

Lever 86 is operated to bring sleeve I and it into engagement and handwheel BI is then rotated to position disc 53 radially from the center of rotation of wheel 49, a distance proportional to the radial distance of the cutting edge of the tool from the axis of rotation of spindle i. The radial position of disc 53 with respect to the center of wheel 49 may be indicated at a suitable work diameter dial associated therewith. Lever 86 is then moved to bring sleeve into engagement with sleeve the drive between cross feed screw rod 5i is effected to automatically in the radial position of disc 51. Thus, the speed of rotation of disc 63 directly reflects the surface speed of the work being cut at any instance.

In order to alter surface cutting speed in increments, as for example, from to 200 feet per minute the change speed mechanism 65 is provided to alter the speed of rotation of gear I! with respect to that of input shaft 65. This change speed mechanism is arranged with a pinrality of intermeshing gears similar to the mechanism 22 employed in connection with the apparatus of Figure 1 of my parent application. If desired, a gear ratio dial may be associated with handwheel lit to indicate the surface speed as in feet per minute obtained by the lntermeshing of the respective gears provided therein. Thus, by doubling the speed of rotation of gear 63 ring gear 62 will be operated in the direction necessary to increase the output speed of transmission 31 whereby rotation of wheel 49 and disc BI is increased to match and equal the increased speed of rotation of gear 88. It is thus seen that the species just described is directly responsive to the surface cutting speed of the work so that said drive shaft 44 75 speed is maintained constant throughout the entire radial movement or the cutting tool with respect to the axis or rotation of a lathe spindle. It will also be seen that the surface cutting speed can be regulated merely by altering the speed ratio between the output shaft N oi the change speed mechanism 65 and the constant speed of the driving shaft II.

While the mechanism herein described discloses a preferred form oi the apparatus, it will be understood that the device is susceptible to numerous changes and substitutions of equivalents. I, therefore, desire to reserve all such changes and substitutions as fall within the scope of the subjoined claims.

Having now described the invention, what I claim and desire to secure by Letters Patent is:

1. In combination with a lathe having a work spindle rotatable on a iixed axis, a toolholder movable toward and from said axis, a motor, a driving connection from said motor to said spindie, and including a variable speed transmission, a wheel connected to said spindle and rotated in timed relation therewith, a friction disc movable radially of said wheel and in driven contact therewith, a shaft splined to said disc, a second shaft connected to said motor and driven in timed relation therewith, joint means driven Jointly by said shafts and connected to said transmission to operate same, and means movable with said holder for radially moving said disc.

2. In a lathe having a work spindle rotatable on an axis, a carriage, a toolholder on said carriage, means moving said holder toward and from said axis, a friction wheel connected to said spindle and rotated at a speed proportional thereto, a

friction disc movable radially of and in contact.

with said wheel, means selectively operable to move said disc manually, or from said holder in accordance with the distance thereof from said axis, a source of power, a connection between said source and spindle including a variable speed transmission having variable speed control means, a diflerential, means driving one sid of said differential from said disc, means driving another side of said diil'erential from said power source, and means driven by the third side of said differential to actuate said variable speed control means for varying the speed oi said transmission.

3. "In a lathe, a work spindle rotatable about a fixed axis, a. power drive connected to rotate said spindle, said power drive including a variable speed transmission having variable speed control means, a cross slide, means mounting said slide for movement toward said axis, a variable speed drive connected to and operated by said spindle, means movable with said slide for adiusting the output speed of said drive in accordance with the position of said slide with respect to said axis, a diflerential having two sides respectively connected to and driven by said variable speed drive and said power drive, and a connection between the third side of said diflerential and said variable speed control means of the transmission to vary the speed of said spindle in accordance with the output speed of said diilerential.

4. In a lathe, a work spindle rotatable on a fixed axis, a power source, a drive from said source to said spindle, including a variable speed transmission, a cross slide mounted for movement toward said axis whereby a tool on said slide may operate upon a workpiece rotated by said spindle, a variable speed drive having input and output elements, said input element being connected to said spindle and driven at a speed a, proportional to the speed of said spindle, a connection adJusting said drive from said sli e. whereby the output element thereoi is driven at a speed proportional to the position of said slide relatively to said axis, a difl'erential having one side driven by the output of said variable speed drive, a connection from said power source driving another side of ,said diflerential, said connection including a change speed mechanism, and a driving connection from the third side of said differential to said variable speed transmission.

5. In a lathe, a work spindle rotatable upon an axis, a power source, a drive from said source to said spindle, including a variable speed transmission, a cross slide mounted for movement toward and from said axis, said slide being adapted to carry a cutting tool for operation upon a workpiece carried by said spindle, a disc connected to said spindle and rotated at a speed directly proportional to said spindle, a friction wheel movable radially over said disc and rotated thereby, a connection between said slide and wheel whereby the radial position of the wheel is proportional to the position of said slide with respect to the spindle axis, a, differential, means connecting one side of said diflerential to said wheel and driving said one side at a speed proportional to said wheel, means connected to said power source for driving a second side of said differential at a speed proportional to that of said power source, and including a manually-operable change speed mechanism, and connection between means the third side of said diilerential and said variable speed transmission.

6. In a lathe, a work spindle rotatable upon an axis, a tool slide movable toward and from said axis, a motor, a driving connection from said motor to said spindle, including a variable speed transmission having variable speed control means, first means connected to said motor and driven at a speed proportional to the speed of said motor, second means including adjustable speed control means connected to said spindle and driven at a speed proportional to the speed of said spindle, connection means movable with the tool slide and connected to the adjustable speed control means for adjusting the output speed of said second means in accordance with the position of said tool slide with respect to said axis, joint means driven jointly by said first and said second means to compare said speeds, and interconnecting means movable with the said joint means and connected to said variable speed control means for controlling the output speed of said variable speed transmission.

7. In a lathe, a spindle, a motor, driving connections from said motor to rotate said spindle on an axis, said connections including a variable speed transmission having variable speed control means, a tool slide movable toward and from said axis, a differential, first drive means connected to the motor for driving one side of said differential proportional to the speed of said motor, second drive means including adjustable speed means connected to the spindle for driving another side of said diiierential proportional to the speed of said spindle, connection means movable with the tool slide and connected to the adjustable speed control means for adjusting the output speed of said second drive means in accordance with the position or said tool slide with respect to said axis, and means operated by the third side of said differential and connected to said variable speed control means to control said transmission.

8. In a lathe, a spindle, a motor, driving con- IJIQOOO I nections from said motor to rotate said spindle on an axis, said connections including a variable speed transmission having variable speed control means, a tool slide movable toward and from said axis, a diflerential. iirst drive means, said ilrst drive means including a change speed mechanism connected to the motor for drlvina one side of said diiierential proportional to the speed oi said motor, second drive means including adjustable speed control means connected to the spindle for driving another side of said diflerential proportional to the speed of said spindle. connection means movable with the tool slide and connected to the adiustable speed control means for adjusting the output speed of said second drive means in accordance with the position of said tool slide with respect to said axis. and means operated by the third side of said differential and connected to said variable speed control means to control said transmission.

CHFPORD A. BICKEL.

REFERENCES man The iollowina references are of reeosd in the tile 0! this patent:

UNITED STATES PATENTS Number Name Date Smith July 6, in: Clark Ana. 20, 1006 Krauss June 28, 1914 Oliver May 29, 101! Maurer my ii, 103'! Fall: Aug. 16, 1938 Curtis Sept. 9, 1041 Maurer Feb. 8, i042 Bickel Nov. 2'1, 1965 

